Surface-coated particles

Abstract

To provide surface-coated particles that have excellent touch, and can reduce a used amount of synthetic polymer fine particles.SOLUTION: A surface-coated particles in which a part or all of the surface of particles (A) is coated with a surface treating agent (B), where the dynamic friction coefficient of the surface-coated particles is 0.50 or less, and the standard deviation of the dynamic friction coefficient is 0.020 or less, the dynamic friction coefficient being measured under the condition of a load of 3.53 N, a moving speed of 10 mm / sec., a moving distance of 50 mm, a reciprocation frequency of 30 times, and a temperature of 25±2°C after applying 5 mass% ethanol dispersion liquid of the surface-coated particles onto a polyurethane substrate in an amount of 2 mg / cm2, and drying for 24 hours under the atmospheric pressure at 23°C.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to surface-coated particles, surface modifiers, cosmetics, a surface modification method, a method for producing surface-coated particles, and a method for producing feel-enhancing particles. [Background technology]

[0002] BACKGROUND ART Synthetic polymer particles are sometimes blended into cosmetics, skin care products, toiletry products, perfumes, and other cosmetic products in order to improve the feel of the product to the touch. However, since synthetic polymer particles are difficult to decompose in the natural environment and there is a concern that they may have a negative impact on the ecosystem, there is a demand for particles that improve the feel of the material as an alternative to synthetic polymer particles. Furthermore, examples of texture-improving particles incorporated into cosmetics include inorganic particles whose surfaces are coated with a silicone compound. Technologies relating to such surface-coated particles include those described in Patent Documents 1 and 2, for example.

[0003] Patent Document 1 describes inorganic particles whose surfaces are coated with poly(N-acylalkyleneimine)-modified silicone. Patent Document 2 describes a composite surface-treated inorganic powder in which a base powder mainly made of an inorganic material is surface-treated with a cationic surfactant and amino-modified silicone. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-301826 [Patent Document 2] International Publication No. 2020 / 230650 Summary of the Invention [Problem to be solved by the invention]

[0005] There is a need for feel-enhancing particles that provide a good feel and allow for a reduction in the amount of synthetic polymer particles used. One embodiment of the present invention relates to providing surface-coated particles, a surface modifier, and a cosmetic product that have a good feel and can reduce the amount of synthetic polymer fine particles used, as well as a surface modification method using the surface-coated particles, the surface modifier, or the cosmetic product. Furthermore, one embodiment of the present invention relates to providing a method for producing surface-coated particles that have a good feel and can reduce the amount of synthetic polymer particles used. Furthermore, one embodiment of the present invention relates to providing a method for producing feel-enhancing particles that have a good feel and can reduce the amount of synthetic polymer particles used. [Means for solving the problem]

[0006] The present invention relates to the following [1] to [6]. [1] Surface-coated particles in which part or all of the surface of a particle (A) is coated with a surface treatment agent (B), A 5% by mass ethanol dispersion of the surface-coated particles was applied to a polyurethane substrate at a concentration of 2 mg / cm 2 and drying for 24 hours at 23°C and atmospheric pressure, the coefficient of dynamic friction of the surface-coated particles is 0.50 or less, as measured under the conditions of a load of 3.53 N, a moving speed of 10 mm / sec, a moving distance of 50 mm, 30 reciprocations, and a temperature of 25±2°C; The surface-coated particles have a standard deviation of the dynamic friction coefficient of 0.020 or less. [2] A surface modifier comprising the surface-coated particles described in [1] above. [3] A cosmetic product comprising the surface-coated particles described in [1] above. [4] A surface modification method comprising a step of applying the surface-coated particles described in [1], the surface modifier described in [2], or the cosmetic product described in [3] to a target surface. [5] A method for producing surface-coated particles according to [1], comprising a step of mixing the particles (A) with a surface treatment agent solution containing the surface treatment agent (B) and a solvent. [6] A method for producing feel-improving particles, comprising a step of selecting, from surface-coated particles in which part or all of the surface of a particle (A) is coated with a surface treatment agent (B), particles having a dynamic friction coefficient of 0.50 or less, measured by the following method, and a standard deviation of the dynamic friction coefficient of 0.020 or less, as feel-improving particles. (method) A 5% by mass ethanol dispersion of the surface-coated particles was applied to a polyurethane substrate at a concentration of 2 mg / cm 2 After drying for 24 hours at 23°C and atmospheric pressure, the test is carried out under the following conditions: load 3.53N, moving speed 10mm / sec, moving distance 50mm, number of reciprocations 30, and temperature 25±2°C. [Effects of the Invention]

[0007] According to one embodiment of the present invention, it is possible to provide surface-coated particles, a surface modifier, and a cosmetic product that have a pleasant feel and can reduce the amount of synthetic polymer fine particles used, as well as a surface modification method using the surface-coated particles, the surface modifier, or the cosmetic product. Furthermore, according to one embodiment of the present invention, it is possible to provide a method for producing surface-coated particles that have a good feel and can reduce the amount of synthetic polymer particles used. Furthermore, one embodiment of the present invention can provide a method for producing feel-enhancing particles that have a good feel and can reduce the amount of synthetic polymer particles used. DETAILED DESCRIPTION OF THE INVENTION

[0008] [Surface coated particles] The surface-coated particles according to the present invention are particles (A) whose surfaces are partially or entirely coated with a surface treatment agent (B), and a 5% by mass ethanol dispersion of the surface-coated particles is applied to a polyurethane substrate at a concentration of 2 mg / cm. 2and drying for 24 hours at 23°C under atmospheric pressure, the kinetic friction coefficient of the surface-coated particles is measured under conditions of a load of 3.53 N, a movement speed of 10 mm / sec, a movement distance of 50 mm, 30 reciprocations, and a temperature of 25±2°C, and the kinetic friction coefficient is 0.50 or less, and the standard deviation of the kinetic friction coefficient is 0.020 or less. Here, in measuring the kinetic friction coefficient and kinetic friction coefficient of the surface-coated particles, for example, a measurement jig in which a polyurethane substrate is fixed to a 3 cm x 3 cm indenter can be used.

[0009] The surface-coated particles according to the present invention have a pleasant feel to the touch. Therefore, when the surface-coated particles according to the present invention are incorporated into or used as a cosmetic product, the tactile feel of the cosmetic product can be improved. Furthermore, when the surface-coated particles according to the present invention are used as a surface modifier, the surfaces of skin, hair, nails, etc. can be modified to have a pleasant feel to the touch. Furthermore, the surface-coated particles according to the present invention can utilize particles that do not fall under the category of synthetic polymer fine particles as core particles, which is environmentally friendly and allows the amount of synthetic polymer fine particles used to be reduced.

[0010] In this specification, "the surface of the particle (A) is partially or entirely coated with the surface treatment agent (B)" means that the surface treatment agent (B) is adsorbed to at least a portion of the surface of the particle (A) via intermolecular forces or ionic bonds. The term "adsorbed" does not include a state in which the particle (A) and the surface treatment agent (B) are covalently bonded to each other. Whether or not the surface treatment agent (B) is adsorbed to at least a part of the surface of the particles (A) is determined by a known method. For example, when the adsorption amount of the surface treatment agent (B) per 100 parts by mass of the particles (A), calculated by "Measurement of the amount of adsorption of the surface treatment agent to inorganic particles" described in the Examples, is more than 0 parts by mass, preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, it is determined that the surface treatment agent (B) is adsorbed to the surface of the inorganic particles (A). In this specification, "feel" refers to the smoothness and lack of squeaky feeling of the particles when applied to skin, hair, nails, etc. The smoother and less squeaky feeling the better the feel. "Smoothness" refers to a feel that is smooth and not powdery, and "squeaky feeling" refers to a feeling that the particles catch when the fingers are brought into contact with and moved over the skin, hair, nails, etc.

[0011] The dynamic friction coefficient of the surface-coated particles according to the present invention is 0.50 or less, but from the viewpoint of further improving the feel, it is preferably 0.45 or less, more preferably 0.43 or less, even more preferably 0.40 or less, even more preferably 0.35 or less, even more preferably 0.32 or less, even more preferably 0.30 or less, even more preferably 0.29 or less, even more preferably 0.28 or less, even more preferably 0.26 or less. The lower limit of the dynamic friction coefficient is not particularly limited, but may be, for example, 0.10 or more, 0.13 or more, 0.16 or more, or 0.18 or more. The dynamic friction coefficient of the surface-coated particles according to the present invention can be measured specifically by the method described in the Examples.

[0012] The standard deviation of the dynamic friction coefficient of the surface-coated particles according to the present invention is 0.020 or less, and from the viewpoint of further improving the feel, it is preferably 0.018 or less, more preferably 0.017 or less, and even more preferably 0.016 or less. The lower limit of the standard deviation of the dynamic friction coefficient is not particularly limited, but may be, for example, 0.001 or more, 0.003 or more, 0.005 or more, or 0.006 or more. The standard deviation of the dynamic friction coefficient of the surface-coated particles according to the present invention can be measured specifically by the method described in the Examples.

[0013] From the viewpoint of further improving environmental compatibility, the content of the water-insoluble synthetic polymer that is solid at 25°C in the surface-coated particles according to the present invention is preferably less than 1% by mass, more preferably less than 0.5% by mass, even more preferably less than 0.1% by mass, and even more preferably less than 0.01% by mass, and it is preferable that the surface-coated particles according to the present invention are substantially free of the synthetic polymer. In this specification, "substantially free of the synthetic polymer" means that it is not intentionally added, and does not exclude the presence of a small amount of the synthetic polymer as an impurity. As used herein, the term "water-insoluble synthetic polymer" refers to a synthetic polymer that dissolves in an amount of 2 g or less when 10 g of the synthetic polymer is mixed with 1,000 mL of water at 20°C and pH 7 in accordance with OECD guideline 120 and stirred for 24 hours. Furthermore, "solid at 25°C" refers to a state in which the substance does not have fluidity in a bulk state under 1 atmosphere at 25°C.

[0014] The volume median particle size (D 50 From the viewpoint of further improving the feel, the thickness is preferably more than 1 μm, more preferably more than 2 μm, and even more preferably more than 3 μm, and is preferably 30 μm or less, more preferably 20 μm or less, even more preferably 15 μm or less, and even more preferably 12 μm or less. Here, the volume median particle size (D 50 ) is the 50% median diameter measured by a particle size distribution analyzer using a laser diffraction / scattering method, and specifically can be measured by the method described in the examples.

[0015] In the surface-coated particles according to the present invention, from the viewpoint of further improving the feel, the surface treatment agent (B) is preferably adsorbed to the surface of the particle (A) via an intermolecular force or an ionic bond. In this specification, whether or not the particles (A) and the surface treatment agent (B) are adsorbed due to intermolecular forces or ionic bonds can be confirmed by a known method, for example, by observing the change in the amount of adsorption after washing the surface-coated particles with a solvent in which the surface treatment agent (B) is soluble, and specifically, by the method described in the Examples.

[0016] Hereinafter, each component constituting the surface-coated particles according to the present invention and a method for producing the surface-coated particles will be described in order.

[0017] <Particle (A)> From the viewpoint of further improving the feel and environmental compatibility of the surface-coated particles, the particles (A) preferably contain at least one selected from inorganic particles (A1) and polysaccharide particles (A2). Since the inorganic particles (A1) and polysaccharide particles (A2) do not fall under the category of synthetic polymer fine particles, surface-coated particles having at least one selected from the inorganic particles (A1) and polysaccharide particles (A2) as core particles have improved environmental compatibility and are more suitable as a substitute for synthetic polymer fine particles. From the viewpoint of further improving the feel and environmental compatibility of the surface-coated particles, the total content of the inorganic particles (A1) and the polysaccharide particles (A2) in the particles (A) is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and preferably 100% by mass or less. Furthermore, from the viewpoint of further improving the feel and environmental compatibility of the surface-coated particles, the content of synthetic polymer fine particles in particles (A) is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 10% by mass or less, even more preferably 5% by mass or less, and even more preferably 2% by mass or less, and it is even more preferable that particles (A) are substantially free of synthetic polymer fine particles. Here, "substantially free of synthetic polymer fine particles" means that the particles may contain synthetic polymer fine particles unintentionally present as impurities.

[0018] From the viewpoint of further improving the feel of the surface-coated particles, the inorganic particles (A1) preferably contain silica particles or silicate mineral particles, more preferably contain at least one type of particle selected from silica particles, talc particles, and mica particles, and even more preferably contain at least one type of particle selected from silica particles and mica particles. From the viewpoint of further suppressing stickiness at the dry stage, it is even more preferable that they contain silica particles, and even more preferable that they contain porous silica particles. From the viewpoint of further improving the feel of the surface-coated particles, the silicate mineral particles preferably contain at least one selected from talc particles, mica particles, sericite particles, smectite particles, montmorillonite particles, bentonite particles, and kaolin particles, more preferably contain at least one selected from talc particles and mica particles, and even more preferably contain mica particles. The polysaccharide particles (A2) preferably contain cellulose particles.

[0019] When the inorganic particles (A1) contain porous silica particles, the specific surface area of ​​the porous silica particles is preferably 5 m from the viewpoint of suppressing the collapse of the porous silica particles and further improving the feel of the surface-coated particles. 2 / g or more, more preferably 10m 2 / g or more, and preferably 1000m 2 / g or less, more preferably 900m 2 / g or less. The specific surface area is a BET specific surface area measured in accordance with JIS Z 8830:2013.

[0020] When the inorganic particles (A1) contain porous silica particles, the pore volume of the porous silica particles is preferably 0.1 mL / g or more, more preferably 0.3 mL / g or more, even more preferably 0.5 mL / g or more, from the viewpoint of suppressing the collapse of the porous silica particles and further improving the feel of the surface-coated particles, and is preferably 5 mL / g or less, more preferably 3 mL / g or less, even more preferably 2 mL / g or less. Also, from the viewpoint of the absence of a squeaky feel, it is preferably 0.3 mL / g or more, more preferably 0.5 mL / g or more, even more preferably 0.8 mL / g or more, even more preferably 0.9 mL / g or more, and preferably 5 mL / g or less, more preferably 3 mL / g or less, even more preferably 2 mL / g or less. The pore volume can be measured by a gas adsorption method, such as JIS Z 8831-2:2010 (Pore size distribution and pore characteristics of powders (solids) - Part 2: Measurement method for mesopores and macropores by gas adsorption) and JIS Z 8831-3:2010 (Pore size distribution and pore characteristics of powders (solids) - Part 3: Measurement method for micropores by gas adsorption).

[0021] From the viewpoint of further improving the feel of the surface-coated particles, the content of at least one type of particle selected from inorganic particles (A1) and polysaccharide particles (A2) in the particles (A) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and preferably 100% by mass or less. The content of at least one type of particle selected from silica particles and silicate mineral particles in the inorganic particles (A1) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and preferably 100% by mass or less, from the viewpoint of further improving the feel of the surface-coated particles. From the viewpoint of further improving the feel of the surface-coated particles, the content of cellulose particles in the polysaccharide particles (A2) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and preferably 100% by mass or less.

[0022] Examples of the shape of the particles (A) include spherical, plate-like, flaky, irregular, etc. Among these, from the viewpoint of further improving the feel of the surface-coated particles, spherical, plate-like, or flaky shapes are preferred, and spherical or flaky shapes are more preferred. More specifically, when the particles (A) are silica particles or polysaccharide particles (A2), they are more preferably spherical, and when the particles (A) are silicate mineral particles, they are more preferably flaky.

[0023] The volume median diameter (D 50 ) is preferably 1 μm or more, more preferably 2 μm or more, even more preferably 3 μm or more, and is preferably 30 μm or less, more preferably 20 μm or less, even more preferably 15 μm or less, even more preferably 12 μm or less, from the viewpoint of further improving the feel of the surface-coated particles.

[0024] <Surface treatment agent (B)> From the viewpoint of further improving the feel and environmental compatibility of the surface-coated particles, the surface treatment agent (B) preferably contains at least one selected from modified silicone (b1) (hereinafter also referred to as "modified silicone (b1)") that is liquid at 25°C and water-soluble cationic polymer (b2), and from the viewpoint of further suppressing stickiness at the dry stage, it more preferably contains modified silicone (b1) that is liquid at 25°C. In this specification, "liquid at 25°C" refers to a state in which the substance has fluidity in bulk under an environment of 1 atmosphere and 25°C. The modified silicone (b1) and the water-soluble cationic polymer (b2) that are liquid at 25°C do not fall under the category of "synthetic polymers that are solid at 25°C and water-insoluble," and therefore, surface-coated particles that have at least one selected from the modified silicone (b1) and the water-soluble cationic polymer (b2) that are liquid at 25°C as the surface treatment agent (B) have improved environmental compatibility and are more suitable as an alternative material to synthetic polymer microparticles.

[0025] From the viewpoint of further improving the feel and environmental compatibility of the surface-coated particles, the surface treatment agent (B) preferably contains at least one selected from the modified silicone (b1) and the water-soluble cationic polymer (b2) in an amount of 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, still more preferably 90% by mass or more, even more preferably 95% by mass or more, and preferably 100% by mass or less.

[0026] From the viewpoint of improving the feel of the surface-coated particles, the modified silicone (b1) that is liquid at 25°C preferably contains at least one selected from polyether-modified silicone, polyglycerin-modified silicone, branched polyglycerol-modified silicone, and alkyl glyceryl ether-modified silicone, and more preferably contains at least one selected from polyether-modified silicone, polyglycerin-modified silicone, and branched polyglycerol-modified silicone.

[0027] From the viewpoint of further improving the feel of the surface-coated particles, the HLB (hydrophilic-lipophilic balance) of the modified silicone (b1) is preferably 1.0 or more, more preferably 2.0 or more, even more preferably 2.5 or more, and is preferably 20.0 or less, more preferably 18.0 or less, even more preferably 16.0 or less, even more preferably 15.5 or less, even more preferably 15.0 or less, even more preferably 10.0 or less, even more preferably 5.0 or less. Here, the HLB value is a value that indicates the affinity of the modified silicone (b1) for water and oil, and can be calculated by the Griffin method using the following formula: HLB = 20 × [(molecular weight of hydrophilic group contained in modified silicone (b1)) / (molecular weight of modified silicone (b1))] Examples of the hydrophilic group include a hydroxy group and an ethyleneoxy group.

[0028] The viscosity of the modified silicone (b1) at 25°C is preferably 50 mPa·s or more, more preferably 100 mPa·s or more, even more preferably 200 mPa·s or more, even more preferably 400 mPa·s or more, and is preferably 500,000 mPa·s or less, more preferably 100,000 mPa·s or less, even more preferably 80,000 mPa·s or less. The viscosity can be measured at 25°C using a Brookfield viscometer based on JIS Z8803:2011 "Method for measuring viscosity of liquids."

[0029] Polyether-modified silicone has a structure in which the hydrocarbon groups on the side chains and / or terminals of silicone oil are substituted with polyether groups. The polyether group of the polyether-modified silicone is preferably a polyethyleneoxy group, a polypropyleneoxy group, or a polyalkyleneoxy group in which ethyleneoxy groups (EO) and propyleneoxy groups (trimethyleneoxy groups or propane-1,2-diyloxy groups; PO) are added in a block or random manner, and more preferably a polyethyleneoxy group. The polyether-modified silicone may be a compound in which a polyether group is grafted onto a silicone main chain, or a compound in which silicone and polyether groups are bonded in a block manner.

[0030] From the viewpoint of further improving the feel of the surface-coated particles, the viscosity of the polyether-modified silicone at 25°C is preferably 50 mPa·s or more, more preferably 100 mPa·s or more, even more preferably 200 mPa·s or more, even more preferably 400 mPa·s or more, and even more preferably 450 mPa·s or more, and is preferably 3000 mPa·s or less, more preferably 2000 mPa·s or less, even more preferably 1000 mPa·s or less, even more preferably 750 mPa·s or less, and even more preferably 600 mPa·s or less. The viscosity can be measured at 25°C using a Brookfield viscometer based on JIS Z8803:2011 "Method for measuring viscosity of liquids."

[0031] Specific examples of polyether-modified silicones include PEG-3 dimethicone, PEG-9 dimethicone, PEG-9 methyl ether dimethicone, PEG-10 dimethicone, PEG-11 methyl ether dimethicone, PEG-12 dimethicone, PEG / PPG-20 / 22 butyl ether dimethicone, PEG-32 methyl ether dimethicone, PEG-9 polydimethylsiloxyethyl dimethicone, lauryl PEG-9 polydimethylsiloxyethyl dimethicone, cetyl PEG / PPG-10 / 1 dimethicone, PEG / PPG-30 / 10 dimethicone, and linear polyether-modified silicones in which dimethyl silicone units and polyether units are alternately copolymerized. Examples of commercially available polyether-modified silicones include the KF series (e.g., KF-6004, KF-6011, KF-6012, KF-6013, KF-6015, KF-6016, KF-6017, KF-6028, KF-6038, KF-6043, KF-6048) manufactured by Shin-Etsu Chemical Co., Ltd., and the DOWSIL series (BY25-339, SH3775M, FZ-2203) manufactured by Dow Chemical Japan Ltd.

[0032] Polyglycerin-modified silicone refers to silicone having a monovalent polyglyceryl group in its structure, and examples include polyglyceryl-3 disiloxane dimethicone, polyglyceryl-3 polydimethylsiloxyethyl dimethicone, lauryl polyglyceryl-3 polydimethylsiloxyethyl dimethicone, etc. Here, in this specification, branched polyglycerol-modified silicones are excluded from polyglycerin-modified silicones. Commercially available polyglycerin-modified silicone products include, for example, the KF series (for example, KF-6100, KF-6104, KF-6106, and KF-6105) manufactured by Shin-Etsu Chemical Co., Ltd.

[0033] From the viewpoint of further improving the feel of the surface-coated particles, the viscosity of the polyglycerin-modified silicone at 25°C is preferably 500 mPa·s or more, more preferably 1,000 mPa·s or more, even more preferably 2,000 mPa·s or more, and even more preferably 3,000 mPa·s or more, and is preferably 20,000 mPa·s or less, more preferably 10,000 mPa·s or less, even more preferably 5,000 mPa·s or less, and even more preferably 4,000 mPa·s or less. The viscosity can be measured at 25°C using a Brookfield viscometer based on JIS Z8803:2011 "Method for measuring viscosity of liquids."

[0034] An example of a branched polyglycerol-modified silicone is a compound represented by the following formula (1), which has a structure in which branched polyglycerol chains are bonded to both ends of a dimethylpolysiloxane via linking groups containing oxyphenylene groups.

[0035] [ka] (In formula (1), R 12 each independently represents a branched polyglycerol chain, and m represents an integer of 0 to 10,000.

[0036] In formula (1), the bonding mode between the oxygen atom in the phenylene group portion and the trimethylene group (-C3H6-) is not particularly limited, and may be at the ortho, meta, or para position. m represents an integer of 0 to 10,000, preferably 1 to 300. R 12 represents a branched polyglycerol chain, which is composed of glycerol units represented by the following structural formulas (2) to (5), has at least one glycerol unit having a branched structure represented by structural formula (2), and terminates with a glycerol unit represented by structural formula (5). The average total number of glycerol units bonded in the branched polyglycerol chain is 3 or more and 200 or less, and preferably 3 or more and 30 or less.

[0037] [ka]

[0038] From the viewpoint of further improving the feel of the surface-coated particles, the viscosity of the branched polyglycerol-modified silicone at 25°C is preferably 10,000 mPa·s or more, more preferably 20,000 mPa·s or more, even more preferably 40,000 mPa·s or more, even more preferably 60,000 mPa·s or more, even more preferably 70,000 mPa·s or more, and preferably 500,000 mPa·s or less, more preferably 100,000 mPa·s or less, even more preferably 80,000 mPa·s or less. The viscosity can be measured at 25°C using a Brookfield viscometer in accordance with JIS Z8803:2011 "Method for measuring viscosity of liquids."

[0039] The branched polyglycerol-modified silicone represented by formula (1) can be produced by, for example, the method described in JP 2004-339244 A, in which 2,3-epoxy-1-propanol is added to a modified silicone having phenyl groups substituted with hydroxy groups at both ends, in the presence of an acidic or basic catalyst, and the resulting mixture is subjected to graft polymerization, or by other commonly known methods. Furthermore, examples of commercially available branched polyglycerol-modified silicones include SOFCARE GS-G (manufactured by Kao Corporation).

[0040] Examples of alkyl glyceryl ether-modified silicones include those represented by the following formula (6).

[0041] [ka] [In formula (6), Q represents a divalent hydrocarbon group having 3 to 20 carbon atoms, and R 1 ~R 9 may be the same or different and represent a hydrogen atom, a linear or branched hydrocarbon group having 1 to 32 carbon atoms, or a phenyl group; R 10 and R 11 may be the same or different and represent a hydrogen atom or a linear or branched hydrocarbon group having 1 to 32 carbon atoms; multiple R 10 and R 11 may be different from each other. p is a number of 1 or more and 500 or less, and q is a number of 1 or more and 50 or less. In addition, p and q are alkyl glyceryl ether groups [-Q-OCH2-CH(OR 10 )-CH2(OR 11 It is preferable that the content of (a) is 1% by mass or more and 50% by mass or less.)

[0042] In formula (6), the divalent hydrocarbon group having 3 to 20 carbon atoms represented by Q is preferably a linear or branched alkylene group having 3 to 20 carbon atoms. More specific examples include linear alkylene groups such as trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene, dodecamethylene, tetradecamethylene, hexadecamethylene, and octadecamethylene; and branched alkylene groups such as propylene, 2-methyltrimethylene, 2-methyltetramethylene, 2-methylpentamethylene, and 3-methylpentamethylene.

[0043] Also, R 1 ~R 11 In the definition of R, examples of the straight-chain or branched-chain hydrocarbon group having 1 to 32 carbon atoms include straight-chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, undecyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, doeicosyl, tetraeicosyl, hexaeicosyl, octaeicosyl, and triacontyl; and branched-chain alkyl groups such as isopropyl, sec-butyl, tert-butyl, neopentyl, 1-ethylpropyl, and 1-heptyldecyl. 1 ~R 9 is preferably a linear or branched alkyl group having 1 to 25 carbon atoms (some of which may be hydrogen atoms), and more preferably a linear or branched alkyl group having 1 to 22 carbon atoms (some of which may be hydrogen atoms). 10 , R 11 is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom.

[0044] Furthermore, p and q are alkyl glyceryl ether groups [-Q-OCH2-CH(OR 10 )-CH2(OR 11 The number is preferably such that the content of (a) is 1% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 40% by mass or less, and even more preferably 10% by mass or more and 30% by mass or less. Specifically, from the standpoint of ease of availability of the organopolysiloxane used as a raw material and operability during production, p is in the range of 1 to 500, preferably 10 to 30, and q is in the range of 1 to 50, preferably 1 to 30.

[0045] From the viewpoint of further improving the feel of the surface-coated particles, the viscosity of the alkyl glyceryl ether-modified silicone at 25°C is preferably 1,000 mPa·s or more, more preferably 2,000 mPa·s or more, even more preferably 3,000 mPa·s or more, even more preferably 4,000 mPa·s or more, even more preferably 5,000 mPa·s or more, even more preferably 6,000 mPa·s or more, and preferably 20,000 mPa·s or less, more preferably 10,000 mPa·s or less, even more preferably 8,000 mPa·s or less, even more preferably 7,000 mPa·s or less. The viscosity can be measured at 25°C using a Brookfield viscometer in accordance with JIS Z8803:2011 "Method for measuring viscosity of liquids."

[0046] Such alkyl glyceryl ether-modified silicones can be produced by reacting an organohydrogenpolysiloxane having at least one silicon-hydrogen bond with the corresponding alkenyl glyceryl ether according to the methods described in JP-A-4-134013 and JP-A-2005-194523. Commercially available alkyl glyceryl ether-modified silicones include, for example, SI-UGE and Softcare RS-U (both manufactured by Kao Corporation).

[0047] These modified silicones (b1) may be used alone or in combination of two or more.

[0048] From the viewpoint of further improving the feel and environmental compatibility of the surface-coated particles, the water-soluble cationic polymer (b2) preferably contains at least one selected from cationic polymers having a cellulose skeleton, cationic vinyl polymers, chitin / chitosans, and halogenated hexadimethrine, more preferably contains at least one selected from cationic polymers having a cellulose skeleton, cationic vinyl polymers, chitin / chitosans, hexadimethrine bromide, and hexadimethrine chloride, still more preferably contains at least one selected from cationic polymers having a cellulose skeleton, cationic vinyl polymers, and chitin / chitosans, and even more preferably contains at least one selected from cationic polymers having a cellulose skeleton and cationic vinyl polymers. As used herein, the term "water-soluble polymer" refers to a polymer that dissolves in an amount of more than 2 g when 10 g of the polymer is mixed with 1000 mL of water at 20°C and pH 7 and allowed to stand for 24 hours. The water-soluble cationic polymer (b2) preferably has a basic group such as a primary to tertiary amino group, a quaternary ammonium group, or a hydrazino group, and more preferably a tertiary amino group or a quaternary ammonium group. The basic group includes those neutralized with acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, maleic acid, fumaric acid, citric acid, tartaric acid, adipic acid, and lactic acid. In this specification, the water-soluble cationic polymer (b2) excludes water-soluble cationic silicones such as water-soluble amino-modified silicones.

[0049] From the viewpoint of improving the feel of the surface-coated inorganic particles, the weight-average molecular weight Mw of the water-soluble cationic polymer (b2) is preferably 3,000 or more, more preferably 5,000 or more, even more preferably 15,000 or more, even more preferably 50,000 or more, and even more preferably 100,000 or more, and is preferably 5 million or less, more preferably 3 million or less, and even more preferably 2 million or less. The above weight-average molecular weight Mw can be measured by gel permeation chromatography (GPC) using polyethylene glycol as a standard substance. For example, the weight-average molecular weight Mw of cationized hydroxyethyl cellulose, which is a water-soluble cationic polymer (b2), can be determined by performing GPC measurement under the following conditions. <GPC Measurement Conditions> Sample concentration: 1 mg / mL Column: TSKgel α-M × 2 columns (Tosoh Corporation) Eluent: 0.15 mol / L aqueous sodium sulfate solution (containing 1% acetic acid) Flow rate: 1.0 mL / min Column temperature: 40 °C Detector: Differential refractive index detector

[0050] In this specification, the "cationic polymer having a cellulose backbone" means a polymer having a cationic group and a cellulose backbone and being a cationic charge as a whole. The cationic group refers to a cationic group or a group that can be ionized to become a cationic group, and examples thereof include a primary amino group, a secondary amino group, a tertiary amino group, a quaternary ammonium group, etc. Examples of the cationic polymer having a cellulose backbone include cationized cellulose, cationized cellulose derivatives, etc., and specifically, cationized cellulose, cationized hydroxyethyl cellulose, cationized hydroxypropyl cellulose, cationized carboxymethyl cellulose, etc. can be mentioned. As the cationic polymer having a cellulose backbone, cationized hydroxyethyl cellulose is preferred, and a polymer of a quaternary ammonium salt (INCI name: Polyquaternium-10) obtained by adding glycidyltrimethylammonium chloride to hydroxyethyl cellulose is more preferred.

[0051] Examples of cationic vinyl polymers include vinylpyrrolidone / dimethylaminoethyl methacrylate copolymer diethyl sulfate, vinylpyrrolidone / dimethylaminopropyl methacrylamide / lauryldimethylaminopropyl methacrylamide copolymer, vinylpyrrolidone / N,N-dimethylaminoethyl methacrylate / alkyl acrylate / tripropylene glycol diacrylate copolymer, polydimethylmethylenepiperidinium chloride, dimethyldiallylammonium chloride / acrylamide copolymer, trimethylammoniopropylacrylamide chloride / dimethylacrylamide copolymer, alkylacrylamide / acrylate / alkylaminoalkylacrylamide, Examples of suitable copolymers include vinylpyrrolidone / polyethylene glycol methacrylate copolymer, t-butylacrylamide / dimethylacrylamide / dimethylaminopropylacrylamide / methoxypolyethylene glycol methacrylate copolymer, vinylpyrrolidone / N,N-dimethylaminoethyl methacrylic acid copolymer diethyl sulfate, vinylpyrrolidone / dimethylaminoethyl methacrylate copolymer, N,N-dimethylaminoethyl methacrylic acid diethyl sulfate / N,N-dimethylacrylamide / polyethylene glycol dimethacrylate copolymer, ammonium-modified hydroxyethyl cellulose, acrylamide / DMAPA acrylate / PEG methoxy methacrylate copolymer, etc. Among these, tertiary amino group-containing (meth)acrylic polymers are preferred, and acrylamide / DMAPA acrylate / PEG methoxy methacrylate copolymer is more preferred.

[0052] Examples of chitin / chitosan include chitin / chitosan derivatives such as hydroxypropyl chitosan, carboxymethyl chitin, and carboxymethyl chitosan, as well as chitin and chitosan, with chitosan being preferred.

[0053] These water-soluble cationic polymers (b2) may be used alone or in combination of two or more.

[0054] The surface treatment agent (B) may contain a surface treatment agent other than the modified silicone (b1) and the water-soluble cationic polymer (b2). Examples of the surface treatment agent other than the modified silicone (b1) and the water-soluble cationic polymer (b2) include surface treatment agents used for cosmetic particles.

[0055] The content of at least one selected from the modified silicone (b1) and the water-soluble cationic polymer (b2) that are liquid at 25°C in the surface treatment agent (B) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and preferably 100% by mass or less, from the viewpoint of further improving the feel of the surface-coated particles and further improving environmental compatibility.

[0056] From the viewpoint of further improving environmental compatibility, the content of the water-insoluble synthetic polymer that is solid at 25°C in the surface treatment agent (B) is preferably less than 10% by mass, more preferably less than 5% by mass, even more preferably less than 1% by mass, even more preferably less than 0.1% by mass, and even more preferably less than 0.01% by mass, and it is preferable that the surface treatment agent (B) is substantially free of such synthetic polymer.

[0057] In the surface-coated particles according to the present invention, the amount of surface treatment agent (B) adsorbed to particles (A) is, from the viewpoint of further improving the feel, preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 0.7 parts by mass or more, even more preferably 0.9 parts by mass or more, even more preferably 1.0 parts by mass or more, even more preferably 1.5 parts by mass or more, even more preferably 2.0 parts by mass or more, even more preferably 2.5 parts by mass or more, even more preferably 3.5 parts by mass or more, even more preferably 4.5 parts by mass or more, even more preferably 5.5 parts by mass or more, even more preferably 6.5 parts by mass or more, and is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, even more preferably 13 parts by mass or less, even more preferably 10 parts by mass or less, even more preferably 8.5 parts by mass or less, and even more preferably 7.5 parts by mass or less, per 100 parts by mass of particles (A). The amount of adsorption of the surface treatment agent (B) can be measured by the method described in the examples.

[0058] [Method of manufacturing surface-coated particles] The surface-coated particles according to the present invention can be obtained by coating particles (A) with a surface treatment agent (B). Specifically, from the viewpoint of coating particles (A) with surface treatment agent (B), the method for producing surface-coated particles preferably includes, for example, a step of mixing particles (A) with a surface treatment agent solution containing surface treatment agent (B) and an organic solvent, and more preferably includes a step of mixing a particle dispersion containing particles (A) and solvent A with a surface treatment agent solution containing surface treatment agent (B) and solvent B. The solvent may be water or an organic solvent. The organic solvent is not particularly limited, but may be, for example, an alcohol such as methanol, ethanol, 1-propanol, or 2-propanol. Among the alcohols, at least one selected from ethanol and 2-propanol is more preferred, and ethanol is even more preferred.

[0059] The solvent A and the solvent B may be the same or different from each other as long as they are compatible with each other. The solvent A used in the particle dispersion is preferably at least one selected from water and ethanol, from the viewpoint of dispersibility of the particles (A). When the surface treatment agent (B) contains a modified silicone (b1), the solvent used for the surface treatment agent solution is preferably an organic solvent from the viewpoint of the solubility of the modified silicone (b1), and more preferably ethanol from the viewpoint of compatibility with the solvent A. When the surface treatment agent (B) contains a water-soluble cationic polymer (b2), the solvent used in the surface treatment agent solution is preferably at least one selected from water and ethanol, more preferably water, from the viewpoint of the solubility of the water-soluble cationic polymer (b2). Furthermore, from the viewpoint of improving the solubility of the water-soluble cationic polymer (b2), an organic acid such as lactic acid may be further added to the surface treatment agent solution.

[0060] When the particle dispersion is used, the concentration of the particles (A) in the particle dispersion is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, from the viewpoint of efficiently adsorbing the surface treatment agent (B) onto the surfaces of the particles (A), and is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and even more preferably 10% by mass or less. When the surface treatment agent solution is used, the concentration of the surface treatment agent (B) in the surface treatment agent solution is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, from the viewpoint of efficiently adsorbing the surface treatment agent (B) onto the surface of the particles (A), and is also preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and even more preferably 10% by mass or less.

[0061] The temperature when mixing the particles (A) or the particle dispersion with the surface treatment agent solution is preferably 5°C or higher, more preferably 10°C or higher, from the viewpoint of efficiently adsorbing the surface treatment agent (B) onto the surface of the particles (A), and is preferably 70°C or lower, more preferably 50°C or lower, from the viewpoint of suppressing evaporation of the solvent. The mixing time of the particles (A) or the particle dispersion with the surface treatment agent solution is preferably 5 minutes or more, more preferably 10 minutes or more, from the viewpoint of sufficient adsorption of the surface treatment agent (B) on the surface of the particles (A), and is preferably 12 hours or less, more preferably 6 hours or less, from the viewpoint of production efficiency. In the step of mixing the particles (A) or the particle dispersion with the surface treatment agent solution, a known stirring device can be used.

[0062] The mixture obtained by the above step can be separated using a known method such as centrifugation, filtration, decantation, drying, etc., to recover the surface-coated particles. The obtained surface-coated particles may be classified using a sieve or the like to adjust the particle size.

[0063] [Surface modifier] The surface-coated particles according to the present invention can be applied to a surface modifier. That is, the surface modifier according to the present invention includes the surface-coated particles according to the present invention. In this specification, the term "surface modifier" refers to an agent that can improve the feel of the surface of skin, hair, nails, etc. The content of the surface-coated particles of the present invention in the surface modifier of the present invention is not particularly limited, as it is set appropriately depending on the type of surface modifier, but is, for example, 0.1% by mass or more, preferably 1% by mass or more, and, for example, 50% by mass or less, preferably 30% by mass or less, more preferably 10% by mass or less.

[0064] The surface modifier of the present invention can contain optional components used depending on the type of surface modifier, as long as the effects of the present invention are not impaired. Examples of optional components other than the surface-coated particles of the present invention include ultraviolet absorbers, oils, surfactants, water-soluble polymers, thickeners, neutralizing agents, propellants, pH adjusters, disinfectants, anti-inflammatory agents, preservatives, colorants, chelating agents, whitening agents, blood circulation promoters, cooling agents, antiperspirants, insect repellents, physiologically active ingredients, salts, moisturizers, antioxidants, fragrances, plant extracts, etc.

[0065] The surface modifier according to the present invention may be in the form of, for example, a liquid, emulsion, cream, paste, gel, wax, solid, multi-layer, etc. The surface modifier according to the present invention can also be applied to, for example, a sheet, a spray, a mousse, etc. The surface modifier according to the present invention can be applied to, for example, the skin (including the lips), hair, nails, etc., and can be preferably used by painting.

[0066] From the viewpoint of further improving environmental compatibility, the content of synthetic polymer microparticles in the surface modifier of the present invention is preferably less than 0.01% by mass, more preferably less than 0.005% by mass, and even more preferably less than 0.001% by mass. In this specification, the synthetic polymer microparticles are those containing 1% by mass or more of a synthetic polymer that is solid and water-insoluble at 25°C and has a volume median particle diameter (D 50 ) refers to fine particles with a size of 0.1 μm or more and 5 mm or less.

[0067] The method for producing the surface modifier according to the present invention is not particularly limited, and it can be produced, for example, by stirring and mixing the components in a known device.

[0068] [Cosmetics] The surface-coated particles according to the present invention can be incorporated into or applied to various cosmetic products. That is, the cosmetic product according to the present invention contains the surface-coated particles according to the present invention. The content of the surface-coated particles according to the present invention in the cosmetic product according to the present invention is not particularly limited, as it is set appropriately depending on the type of cosmetic product, but is, for example, 0.1% by mass or more, preferably 1% by mass or more, and for example, 50% by mass or less, preferably 30% by mass or less. In this specification, the term "cosmetics" refers to products that come into direct contact with the human body, such as cosmetics, skin care products, toiletry products, and perfumes.

[0069] The cosmetic product according to the present invention may contain optional components used depending on the type of cosmetic product, as long as the effects of the present invention are not impaired. Examples of optional components other than the surface-coated particles according to the present invention include ultraviolet absorbers, oils, surfactants, water-soluble polymers, thickeners, neutralizing agents, propellants, pH adjusters, disinfectants, anti-inflammatory agents, preservatives, colorants, chelating agents, whitening agents, blood circulation promoters, cooling agents, antiperspirants, insect repellents, physiologically active ingredients, salts, moisturizers, antioxidants, fragrances, plant extracts, etc.

[0070] The cosmetic product according to the present invention may be in the form of, for example, a liquid, emulsion, cream, paste, gel, wax, solid, multi-layer, etc. The cosmetic product according to the present invention can also be in the form of, for example, a sheet, a spray, a mousse, etc. The cosmetic product according to the present invention can be applied to, for example, the skin (including the lips), hair, nails, etc., and can be preferably used by painting.

[0071] From the viewpoint of further improving environmental compatibility, the content of synthetic polymer microparticles in the cosmetic product according to the present invention is preferably less than 0.01% by mass, more preferably less than 0.005% by mass, and even more preferably less than 0.001% by mass.

[0072] There are no particular limitations on the method for producing the cosmetic product of the present invention, and it can be produced, for example, by stirring and mixing the components in a known device.

[0073] [Surface modification method] The surface modification method according to the present invention includes the step of applying the above-described surface-coated particles according to the present invention, the above-described surface modifier according to the present invention, or the above-described cosmetic product according to the present invention to a target surface. Examples of the target surface include skin, hair, nails, etc., with skin being preferred. Methods for applying the surface-coated particles, surface modifier, or cosmetic product of the present invention to the target surface include, for example, coating, spraying, or casting onto the target surface, or immersing the target object in the surface-coated particles, surface modifier, or cosmetic product of the present invention.

[0074] [Method of manufacturing texture-enhancing particles] The method for producing feel-improving particles according to the present invention includes a step of selecting, from surface-coated particles in which part or all of the surface of particle (A) is coated with surface treatment agent (B), particles having a dynamic friction coefficient of 0.50 or less and a standard deviation of the dynamic friction coefficient of 0.020 or less, as feel-improving particles, as measured by the following method. (method) A 5% by mass ethanol dispersion of the surface-coated particles was applied to a polyurethane substrate at a concentration of 2 mg / cm 2 After drying for 24 hours at 23°C and atmospheric pressure, the test is carried out under the following conditions: load 3.53N, moving speed 10mm / sec, moving distance 50mm, number of reciprocations 30, and temperature 25±2°C.

[0075] According to the method for producing feel-improving particles of the present invention, feel-improving particles having a good feel can be stably obtained. Furthermore, the feel-improving particles obtained by the method for producing feel-improving particles according to the present invention have a good feel. Therefore, the feel-improving particles according to the present invention can improve the feel of cosmetics by blending them in cosmetics or using them as cosmetics. Furthermore, the feel-improving particles according to the present invention can improve the feel of the surfaces of skin, hair, nails, etc. by using them as a surface modifier. Furthermore, the feel-improving particles according to the present invention can utilize particles that do not fall under the category of synthetic polymer fine particles as core particles, and are therefore environmentally friendly and suitable as an alternative material to synthetic polymer fine particles. The preferred embodiments of the particles (A), the surface treatment agent (B) and the surface-coated particles in the method for producing feel-improving particles according to the present invention, as well as the preferred ranges of the dynamic friction coefficient and the standard deviation of the dynamic friction coefficient, are the same as those of the surface-coated particles according to the present invention described above. [Example]

[0076] The present invention will be described below with reference to examples, but is not limited to the scope of the examples. In these examples and comparative examples, various measurements and evaluations were carried out by the following methods.

[0077] [Measurement and evaluation methods] (1) Measurement of the amount of surface treatment agent adsorbed to particles before surface coating The amount of adsorption of the surface treatment agent was determined by measuring the sample by thermogravimetry-differential thermal analysis (TG-DTA) using a thermal analyzer (Thermo plus EVO2 TG-DTA8122) manufactured by Rigaku Corporation. The measurement conditions were as follows: Sample preparation: Surface-coated particles obtained in the examples and comparative examples and particles before surface coating (approximately 30 mg (precise weighing)) Heating rate: 10℃ / min Measurement temperature range: 35 to 800°C Measurement atmosphere: Air (180 mL / min) From the obtained TG-DTA curve, the amount of the surface treatment agent adsorbed to 100 parts by mass of the particles before surface coating was calculated using the following formula, where the amount of the surface treatment agent adsorbed to the surface-coated particles was defined as x% by mass (the total amount of the surface-coated particles was defined as 100% by mass). Amount of surface treatment agent adsorbed to 100 parts by mass of particles before surface coating (parts by mass) = x / (100 - x) x 100 x is calculated using the following formula: A×x / 100+A×(1-x / 100)×y=B A: Mass (mg) of the surface-coated particle sample B: Mass loss (mg) of surface-coated particles from 100°C to 800°C y: Mass loss rate of particles before surface coating from 100 to 800°C (= mass loss of particles before surface coating from 100 to 800°C / mass of measured sample of particles before surface coating)

[0078] (2) Volume median particle size (D) of particles before and after surface coating 50 ) measurement Using a laser diffraction / scattering particle size analyzer LA-960 manufactured by Horiba Ltd., distilled water was added to the measurement cell, and the particle size distribution of the uncoated particles and the surface-coated particles was measured at a concentration where the absorbance was in the appropriate range. From the particle size distributions obtained, the volume median particle size (D 50) were calculated respectively.

[0079] (3) Measurement of the coefficient of dynamic friction Measured according to the method standardized in JIS K7125:1999. Dynamic friction coefficient μ k is expressed by the following formula 1, where F is the friction force and N is the normal load. F=μ k N (Formula 1) μ k For the measurement, a surface property tester ("Tribogear TYPE: 14" manufactured by Shinto Scientific Co., Ltd.) was used. The surface-modified substrate was fixed to the test table of the tester with double-sided tape, and untreated artificial leather (manufactured by Teijin Cordley Co., Ltd., polyurethane substrate, product name: Cordley (registered trademark) ST2923NY, 3 cm x 10 cm) was fixed to the friction element (3 cm x 3 cm indenter, "ASTM flat indenter" attached to the main body of the surface property tester). A weight of 360 g (vertical load 3.53 N) was placed perpendicular to the friction element, and the artificial leather wrapped around the friction element was brought into contact with the surface-modified substrate and reciprocated in a reciprocating test (travel speed 10 mm / sec, travel distance 50 mm, number of reciprocations 30 (5 reciprocations count as 1 measurement, a total of 6 measurements were performed), temperature 25 ± 2 ° C.). The dynamic friction coefficient obtained after the 30th reciprocation was used. Here, the artificial leather (polyurethane substrate) of the measurement jig was replaced after each measurement (five round trips). The artificial leather was wrapped around the friction element, and the excess part was folded and fixed. The surface-modified substrate was produced by the following method. First, 5% by mass of the particles of the Examples and Comparative Examples and 95% by mass of ethanol were added to a 9 mL screw tube, and the mixture was treated in an ultrasonic cleaner for 2 minutes to obtain a surface modifier. Next, the obtained surface modifier was applied at a concentration of 2 mg / cm to artificial leather ("Cordley (registered trademark) ST2923NY" manufactured by Teijin Cordley Ltd.) consisting of 45% by mass of polyurethane and 55% by mass of polyethylene terephthalate. 2 The mixture was then dried at room temperature (23°C) and atmospheric pressure for 24 hours to obtain a surface-modified substrate.

[0080] (4) Measurement of the standard deviation of the dynamic friction coefficient μk The standard deviation of the coefficient of dynamic friction was measured in the same manner as in the measurement of the coefficient of dynamic friction, and the standard deviation of the coefficient of dynamic friction in the region from 41,000 to 45,000 milliseconds after the start of the test in the sixth measurement (i.e., the 25th to 30th reciprocation) (i.e., the region of the 30th reciprocation in the sixth measurement) was used.

[0081] (5) Sensory evaluation (5-1) Absence of creaking and smoothness In an environment of 20-25°C temperature and 25-40% RH humidity, 0.2 g of the particles obtained in the Examples and Comparative Examples was evenly applied to the inside of the forearm using a finger, and the applied material was rubbed with the finger to evaluate the absence of a squeaky feeling and smoothness, and scored according to the following criteria. Three expert panelists evaluated the feel of each sample shown in the table below in terms of "absence of squeaky feeling" and "smoothness" compared to the reference sample (lauryl methacrylate-ethylene glycol dimethacrylate-sodium methacrylate copolymer particles, volume median particle size (D 50 ): 2 μm, produced according to Example 1 of JP 2006-8980 A) were evaluated in comparison. Samples that were equivalent to the reference sample and felt to be very good in terms of absence of squeaky feeling and smoothness were rated "5", samples that were slightly inferior to the reference sample but felt to be good in terms of absence of squeaky feeling and smoothness were rated "4", samples that were inferior to the reference sample but felt to be average in terms of absence of squeaky feeling and smoothness were rated "3", samples that were inferior to the reference sample and felt to be poor in terms of absence of squeaky feeling and smoothness were rated "2", and samples that were extremely inferior to the reference sample and felt to be very poor in terms of absence of squeaky feeling and smoothness were rated "1", and the average score of the evaluators was used. Each evaluator assigned a score in increments of 0.5, including the middle score. Here, the lauryl methacrylate-ethylene glycol dimethacrylate-sodium methacrylate copolymer particles correspond to polymer particles that are commonly used as texture-improving particles.

[0082] [Production of surface-coated particles] Example 1 A polyglycerin-modified silicone solution was prepared by adding 2 g of the surface treatment agent polyglycerin-modified silicone 1 (polyglyceryl-3 polydimethylsiloxyethyl dimethicone, Shin-Etsu Chemical Co., Ltd. "KF-6104", viscosity at 25°C: 3300 mPa·s) and 98 g of ethanol to a 500 mL beaker. In a separate 500 mL beaker, inorganic particles, such as silica 1 (porous silica particles, manufactured by JGC Catalysts and Chemicals Co., Ltd., "HCS 160M5"), with a volume median particle size (D 50 2 g of cellulose acylate (fibers having a particle size of 5 μm, pore volume of 0.7 mL / g) and 98 g of ethanol were added, and the mixture was treated for 5 minutes at 200 W using an ultrasonic homogenizer (Nippon Seiki Seisakusho, Ultrasonic Homogenizer US-600E) to obtain a particle dispersion. The polyglycerin-modified silicone solution was added to the resulting particle dispersion and stirred at 600 rpm for 1 hour using a magnetic stirrer at room temperature. The resulting mixture was centrifuged at 3000 rpm for 30 minutes using a HITACHI CR21G III centrifuge to separate the particles (dispersoid) and the solution (dispersion medium). After removing the supernatant, the precipitate was dried overnight under reduced pressure at 50°C to obtain surface-coated particles. The resulting surface-coated particles were evaluated. The results are shown in the table.

[0083] Examples 2, 5 to 6, and 8 and Comparative Example 1 Surface-coated particles were obtained in the same manner as in Example 1, except that the types of inorganic particles and surface treatment agents were changed to those shown in the table. The obtained surface-coated particles were evaluated. The results are shown in the table below.

[0084] Examples 3, 7, and 9 Surface-coated particles were obtained in the same manner as in Example 1, except that the types of inorganic particles and surface treatment agent were changed to those shown in the table below and "98 g of ethanol" was changed to "98 g of water." The obtained surface-coated particles were evaluated. The results are shown in the table below.

[0085] Example 4 Surface-coated particles were obtained in the same manner as in Example 1, except that the types of inorganic particles and surface treatment agent were changed to those shown in the table below, "98 g of ethanol" was changed to "98 g of water," and 40 mg of 90% lactic acid (product name: Musashino Lactic Acid 90, manufactured by Musashino Chemical Laboratory Co., Ltd.) was added to the resulting cationic vinyl polymer solution. The resulting surface-coated particles were evaluated. The results are shown in the table below.

[0086] Comparative Example 2 Instead of "Silica 1," "Cellulose 1" (cellulose particles, "CELLULOBEADS D-5" manufactured by Daito Kasei Kogyo Co., Ltd.), volume median particle size (D 50 Cellulose particles were obtained by treating in the same manner as in Example 1, except that "polyglycerin-modified silicone 1" was used and ethanol was used instead of "polyglycerin-modified silicone 2." The obtained cellulose particles were subjected to various evaluations. The results are shown in the table below.

[0087] [Table 1]

[0088] [Table 2]

[0089] The ingredients listed in the table are as follows:

[0090] (particle) Silica 1 (porous silica particles, manufactured by JGC Catalysts and Chemicals Co., Ltd., "HCS 160M5"), volume median particle size (D 50 ):5μm, pore volume:0.7mL / g, spherical) Mica 1 (mica particles, Yamaguchi Mica Co., Ltd. "Y-1800"), volume median particle size (D 50 ):10μm, flaky) Talc 1 (talc particles, Asada Flour Milling Co., Ltd. "JA-13R"), volume median particle size (D 50 ):6μm, flaky) Titanium dioxide 1 (titanium dioxide particles, "MP-100" manufactured by Teika Corporation), volume median particle size (D 50 ):1μm) Cellulose 1 (cellulose particles, Daito Kasei Kogyo Co., Ltd. "CELLULOBEADS D-5"), volume median particle size (D 50 ):5μm)

[0091] (surface treatment agent) Polyglycerin-modified silicone 1 (Polyglyceryl-3 polydimethylsiloxyethyl dimethicone, Shin-Etsu Chemical Co., Ltd. "KF-6104", viscosity at 25°C: 3300 mPa·s) Branched polyglycerol-modified silicone 1 (bis(polyglyceryl-3-oxyphenylpropyl) dimethicone, "SOFCARE GS-G" manufactured by Kao Corporation, viscosity at 25°C: 77,000 mPa·s) Polyether-modified silicone 1 (PEG-10 dimethicone, Shin-Etsu Chemical Co., Ltd. "KF-6017", HLB: 4.5, viscosity at 25°C: 490 mPa·s) Cationic hydroxyethyl cellulose 1 (Polyquaternium-10, Kao Corporation "Poise C-150L") Cationic vinyl polymer 1 (acrylamide / DMAPA acrylate / methoxy PEG methacrylate copolymer, prepared according to Preparation Example 1 below) Hexadimethrine bromide (FUJIFILM Wako Pure Chemical Industries, Ltd. "HCS160M5", Mw: 5,000-10,000)

[0092] Manufacturing Example 1 A four-neck flask equipped with a reflux condenser, a liquid delivery system, a thermometer, a nitrogen gas inlet tube, and a stirrer was heated to 50°C in an oil bath. 100 parts by mass of monomer (monomer mass ratio: N-tert-butylacrylamide / N,N-dimethylacrylamide / methoxypolyethylene glycol monomethacrylate / N-(3-dimethylaminopropyl)acrylamide = 55 / 23 / 20 / 2) was dissolved in 75 parts by mass of ethanol to obtain a monomer solution. Furthermore, 0.2 mol% of initiator (V-65B) relative to the monomer was dissolved in ethanol to a concentration of 5% by mass to obtain an initiator solution. The resulting monomer solution and initiator solution were simultaneously added dropwise to the flask under a nitrogen atmosphere over 130 minutes, and the temperature was maintained at 50°C for 130 minutes and then at 80°C for a further 120 minutes to allow the reaction to proceed. After polymerization, the ethanol solution of the polymer was poured into n-hexane for reprecipitation purification and vacuum dried at 80°C to obtain solid cationic vinyl polymer 1. (Reagents used) N-tert-butylacrylamide (Shinryo Corporation) N,N-dimethylacrylamide (KJ Chemicals Co., Ltd.) Methoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 9 (manufactured by Shin-Nakamura Chemical Co., Ltd., NK Ester M-90G)) N-(3-dimethylaminopropyl)acrylamide (KJ Chemicals Co., Ltd.) V-65B: 2,2'-azobis-(2,4-dimethylvaleronitrile) (Fujifilm Wako Pure Chemical Industries, Ltd.) Ethanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) n-Hexane (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0093] From the table, it can be seen that the surface-coated particles of the Examples are excellent in smoothness and absence of squeaky feeling, and have a good feel. Furthermore, the surface-coated particles of the Examples have core particles that do not fall under the category of synthetic polymer microparticles, and the surface treatment agent does not contain any synthetic polymer that is solid at 25°C and is water-insoluble, so it can be seen that they are environmentally friendly and suitable as an alternative material to synthetic polymer microparticles. [Industrial Applicability]

[0094] According to one embodiment of the present invention, it is possible to provide surface-coated particles, a surface modifier, and a cosmetic product that have a pleasant feel and can reduce the amount of synthetic polymer fine particles used, as well as a surface modification method using the surface-coated particles, the surface modifier, or the cosmetic product. Furthermore, according to one embodiment of the present invention, it is possible to provide a method for producing surface-coated particles that have a good feel and can reduce the amount of synthetic polymer particles used. Furthermore, one embodiment of the present invention can provide a method for producing feel-enhancing particles that have a good feel and can reduce the amount of synthetic polymer particles used.

Claims

1. A surface-coated particle in which a part or all of the surface of the particle (A) is coated with a surface treatment agent (B), A 5% by mass ethanol dispersion of the surface-coated particles was applied to a polyurethane substrate at a concentration of 2 mg / cm 2 and drying for 24 hours at 23°C under atmospheric pressure, the coefficient of dynamic friction of the surface-coated particles is 0.50 or less, as measured under conditions of a load of 3.53 N, a moving speed of 10 mm / sec, a moving distance of 50 mm, 30 reciprocations, and a temperature of 25±2°C, The standard deviation of the dynamic friction coefficient is 0.020 or less.

2. The surface-coated particles according to claim 1 , wherein the particles (A) comprise at least one selected from inorganic particles (A1) and polysaccharide particles (A2).

3. The surface-coated particles according to claim 2 , wherein the inorganic particles (A1) comprise silica particles or silicate mineral particles.

4. The surface-coated particles according to claim 2 , wherein the polysaccharide particles (A2) comprise cellulose particles.

5. 2. The surface-coated particles according to claim 1, wherein the surface treatment agent (B) comprises at least one selected from the group consisting of a modified silicone (b1) and a water-soluble cationic polymer (b2) that are liquid at 25°C.

6. 6. The surface-coated particles according to claim 5, wherein the surface treatment agent (B) contains 50% by mass or more of at least one selected from the modified silicone (b1) and the water-soluble cationic polymer (b2).

7. 6. The surface-coated particle according to claim 5, wherein the modified silicone (b1) comprises at least one selected from polyether-modified silicones, polyglycerin-modified silicones, branched polyglycerol-modified silicones, and alkyl glyceryl ether-modified silicones.

8. 6. The surface-coated particle according to claim 5, wherein the water-soluble cationic polymer (b2) comprises at least one selected from the group consisting of cationic polymers having a cellulose skeleton, cationic vinyl polymers, and chitin-chitosans.

9. 2. The surface-coated particles according to claim 1, wherein the amount of the surface treatment agent (B) adsorbed to the particles (A) is 0.1 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the particles (A).

10. A surface modifier comprising the surface-coated particles according to claim 1.

11. A cosmetic product comprising the surface-coated particles according to claim 1.

12. A surface modification method comprising the step of applying the surface-coated particle according to claim 1, the surface modifier according to claim 10, or the cosmetic according to claim 11 to a target surface.

13. The surface modification method of claim 12, wherein the target surface is skin.

14. The method for producing surface-coated particles according to claim 1 , comprising a step of mixing the particles (A) with a surface-treatment agent solution containing the surface-treatment agent (B) and a solvent.

15. A method for producing feel-improving particles, comprising a step of selecting, from surface-coated particles in which part or all of the surface of a particle (A) is coated with a surface treatment agent (B), particles having a dynamic friction coefficient of 0.50 or less, as measured by the following method, and a standard deviation of the dynamic friction coefficient of 0.020 or less, as feel-improving particles. (method) A 5% by mass ethanol dispersion of the surface-coated particles was applied to a polyurethane substrate at a concentration of 2 mg / cm 2 After drying for 24 hours at 23°C under atmospheric pressure, the test is carried out under the conditions of a load of 3.53N, a moving speed of 10 mm / sec, a moving distance of 50 mm, 30 reciprocations, and a temperature of 25±2°C.